!function ($, window, pluginName, undefined) {
    var containerDefaults = {
            // If true, items can be dragged from this container
            drag: true,
            // If true, items can be droped onto this container
            drop: true,
            // Exclude items from being draggable, if the
            // selector matches the item
            exclude: "",
            // If true, search for nested containers within an item.If you nest containers,
            // either the original selector with which you call the plugin must only match the top containers,
            // or you need to specify a group (see the bootstrap nav example)
            nested: true,
            // If true, the items are assumed to be arranged vertically
            vertical: true
        }, // end container defaults
        groupDefaults = {
            // This is executed after the placeholder has been moved.
            // $closestItemOrContainer contains the closest item, the placeholder
            // has been put at or the closest empty Container, the placeholder has
            // been appended to.
            afterMove: function($placeholder, container, $closestItemOrContainer) {
            },
            // The exact css path between the container and its items, e.g. "> tbody"
            containerPath: "",
            // The css selector of the containers
            containerSelector: "tbody",
            // Distance the mouse has to travel to start dragging
            distance: 0,
            // Time in milliseconds after mousedown until dragging should start.
            // This option can be used to prevent unwanted drags when clicking on an element.
            delay: 0,
            // The css selector of the drag handle
            handle: "",
            // The exact css path between the item and its subcontainers.
            // It should only match the immediate items of a container.
            // No item of a subcontainer should be matched. E.g. for ol>div>li the itemPath is "> div"
            itemPath: "",
            // The css selector of the items
            itemSelector: "tr",


// The class given to "body" while an item is being dragged
            bodyClass: "dragging",
            // The class giving to an item while being dragged
            draggedClass: "dragged",
            // Check if the dragged item may be inside the container.
            // Use with care, since the search for a valid container entails a depth first search
            // and may be quite expensive.
            isValidTarget: function($item, container) {
                return true;
            },
            // Executed before onDrop if placeholder is detached.
            // This happens if pullPlaceholder is set to false and the drop occurs outside a container.
            onCancel: function($item, container, _super, event) {
            },
            // Executed at the beginning of a mouse move event.
            // The Placeholder has not been moved yet.
            onDrag: function($item, position, _super, event) {
                $item.css(position);
            },
            // Called after the drag has been started,
            // that is the mouse button is being held down and
            // the mouse is moving.
            // The container is the closest initialized container.
            // Therefore it might not be the container, that actually contains the item.
            onDragStart: function($item, container, _super, event) {
                $item.css({
                    height: $item.outerHeight(),
                    width: $item.outerWidth()
                });
                $item.addClass(container.group.options.draggedClass);
                $("body").addClass(container.group.options.bodyClass);


            },
            // Called when the mouse button is being released
            onDrop: function($item, container, _super, event) {
                $item.removeClass(container.group.options.draggedClass).removeAttr("style");
                $("body").removeClass(container.group.options.bodyClass);
            },
            // Called on mousedown. If falsy value is returned, the dragging will not start.
            // Ignore if element clicked is input, select or textarea
            onMousedown: function($item, _super, event) {
                if (!event.target.nodeName.match(/^(input|select|textarea)$/i)) {
                    event.preventDefault();
                    return true;
                }
            },
            // The class of the placeholder (must match placeholder option markup)
            placeholderClass: "placeholder",
            // Template for the placeholder. Can be any valid jQuery input
            // e.g. a string, a DOM element.
            // The placeholder must have the class "placeholder"
            placeholder: '<tr class="placeholder"><td colspan="20">&nbsp;</td></tr>',
            // If true, the position of the placeholder is calculated on every mousemove.
            // If false, it is only calculated when the mouse is above a container.
            pullPlaceholder: true,
            // Specifies serialization of the container group.
            // The pair $parent/$children is either container/items or item/subcontainers.
            serialize: function($parent, $children, parentIsContainer) {
                var result = $.extend({}, $parent.data());

                if (parentIsContainer)
                    return [$children];
                else if ($children[0]) {
                    result.children = $children;
                }

                delete result.subContainers;
                delete result.sortable;

                return result;
            },
            // Set tolerance while dragging. Positive values decrease sensitivity,
            // negative values increase it.
            tolerance: 0
        }, // end group defaults
        containerGroups = {},
        groupCounter = 0,
        emptyBox = {
            left: 0,
            top: 0,
            bottom: 0,
            right: 0
        },
        eventNames = {
            start: "touchstart.sortable mousedown.sortable",
            drop: "touchend.sortable touchcancel.sortable mouseup.sortable",
            drag: "touchmove.sortable mousemove.sortable",
            scroll: "scroll.sortable"
        },
        subContainerKey = "subContainers";

    /*
     * a is Array [left, right, top, bottom]
     * b is array [left, top]
     */
    function d(a, b) {
        var x = Math.max(0, a[0] - b[0], b[0] - a[1]),
            y = Math.max(0, a[2] - b[1], b[1] - a[3]);
        return x + y;
    }

    function setDimensions(array, dimensions, tolerance, useOffset) {
        var i = array.length,offsetMethod = useOffset ? "offset" : "position";
        tolerance = tolerance || 0;

        while (i--) {
            var el = array[i].el ? array[i].el : $(array[i]),
                // use fitting method
                pos = el[offsetMethod]();
            pos.left += parseInt(el.css('margin-left'), 10);
            pos.top += parseInt(el.css('margin-top'), 10);
            dimensions[i] = [
                pos.left - tolerance,
                pos.left + el.outerWidth() + tolerance,
                pos.top - tolerance,
                pos.top + el.outerHeight() + tolerance
            ];
        }
    }

    function getRelativePosition(pointer, element) {
        var offset = element.offset();
        return {
            left: pointer.left - offset.left,
            top: pointer.top - offset.top
        }
    }

    function sortByDistanceDesc(dimensions, pointer, lastPointer) {
        pointer = [pointer.left, pointer.top]
        lastPointer = lastPointer && [lastPointer.left, lastPointer.top];

        var dim,
            i = dimensions.length,
            distances = [];

        while (i--) {
            dim = dimensions[i];
            distances[i] = [i, d(dim, pointer), lastPointer && d(dim, lastPointer)];
        }
        distances = distances.sort(function(a, b) {
            return b[1] - a[1] || b[2] - a[2] || b[0] - a[0];
        });

        // last entry is the closest
        return distances;
    }

    function ContainerGroup(options) {
        this.options = $.extend({}, groupDefaults, options);
        this.containers = [];

        if (!this.options.rootGroup) {
            this.scrollProxy = $.proxy(this.scroll, this);
            this.dragProxy = $.proxy(this.drag, this);
            this.dropProxy = $.proxy(this.drop, this);
            this.placeholder = $(this.options.placeholder);
            

            if (!options.isValidTarget)
                this.options.isValidTarget = undefined;
        }
    }

    ContainerGroup.get = function (options) {
        if (!containerGroups[options.group]) {
            if (options.group === undefined)
                options.group = groupCounter++;

            containerGroups[options.group] = new ContainerGroup(options);
        }

        return containerGroups[options.group];
    }

    ContainerGroup.prototype = {
        dragInit: function (e, itemContainer) {
            this.$document = $(itemContainer.el[0].ownerDocument);

            // get item to drag
            var closestItem = $(e.target).closest(this.options.itemSelector);
            // using the length of this item, prevents the plugin from being started if there is no handle being clicked on.
            // this may also be helpful in instantiating multidrag.
            if (closestItem.length) {
                this.item = closestItem;
                this.itemContainer = itemContainer;
                if (this.item.is(this.options.exclude) || !this.options.onMousedown(this.item, groupDefaults.onMousedown, e)) {
                    return;
                }
                this.setPointer(e);
                this.toggleListeners('on');
                this.setupDelayTimer();
                this.dragInitDone = true;
            }
        },
        drag: function (e) {
            if (!this.dragging) {
                if (!this.distanceMet(e) || !this.delayMet)
                    return;

                this.options.onDragStart(this.item, this.itemContainer, groupDefaults.onDragStart, e);
                this.item.before(this.placeholder);
                var draggedHtml = $("#datagrid tbody tr.dragged").html();
               
                $("#datagrid tbody tr.placeholder").html(draggedHtml);
                this.dragging = true;
            }

            this.setPointer(e);
            // place item under the cursor
            this.options.onDrag(this.item,
                getRelativePosition(this.pointer, this.item.offsetParent()),
                groupDefaults.onDrag,
                e);

            var p = this.getPointer(e),
                box = this.sameResultBox,
                t = this.options.tolerance;

            if (!box || box.top - t > p.top || box.bottom + t < p.top || box.left - t > p.left || box.right + t < p.left)
                if (!this.searchValidTarget()) {
                    this.placeholder.detach();
                    this.lastAppendedItem = undefined;
                }
        },
        drop: function (e) {
            this.toggleListeners('off');

            this.dragInitDone = false;

            if (this.dragging) {
                // processing Drop, check if placeholder is detached
                if (this.placeholder.closest("html")[0]) {
                    this.placeholder.before(this.item).detach();
                } else {
                    this.options.onCancel(this.item, this.itemContainer, groupDefaults.onCancel, e);
                }
                this.options.onDrop(this.item, this.getContainer(this.item), groupDefaults.onDrop, e);

                // cleanup
                this.clearDimensions();
                this.clearOffsetParent();
                this.lastAppendedItem = this.sameResultBox = undefined;
                this.dragging = false;
            }
        },
        searchValidTarget: function (pointer, lastPointer) {
            if (!pointer) {
                pointer = this.relativePointer || this.pointer;
                lastPointer = this.lastRelativePointer || this.lastPointer;
            }

            var distances = sortByDistanceDesc(this.getContainerDimensions(),
                    pointer,
                    lastPointer),
                i = distances.length;

            while (i--) {
                var index = distances[i][0],
                    distance = distances[i][1];

                if (!distance || this.options.pullPlaceholder) {
                    var container = this.containers[index];
                    if (!container.disabled) {
                        if (!this.$getOffsetParent()) {
                            var offsetParent = container.getItemOffsetParent();
                            pointer = getRelativePosition(pointer, offsetParent);
                            lastPointer = getRelativePosition(lastPointer, offsetParent);
                        }
                        if (container.searchValidTarget(pointer, lastPointer))
                            return true;
                    }
                }
            }
            if (this.sameResultBox)
                this.sameResultBox = undefined;
        },
        movePlaceholder: function (container, item, method, sameResultBox) {
            var lastAppendedItem = this.lastAppendedItem;
            if (!sameResultBox && lastAppendedItem && lastAppendedItem[0] === item[0])
                return;

            item[method](this.placeholder);
            this.lastAppendedItem = item;
            this.sameResultBox = sameResultBox;
            this.options.afterMove(this.placeholder, container, item);
        },
        getContainerDimensions: function () {
            if (!this.containerDimensions)
                setDimensions(this.containers, this.containerDimensions = [], this.options.tolerance, !this.$getOffsetParent());
            return this.containerDimensions;
        },
        getContainer: function (element) {
            return element.closest(this.options.containerSelector).data(pluginName);
        },
        $getOffsetParent: function () {
            if (this.offsetParent === undefined) {
                var i = this.containers.length - 1,
                    offsetParent = this.containers[i].getItemOffsetParent();

                if (!this.options.rootGroup) {
                    while (i--) {
                        if (offsetParent[0] != this.containers[i].getItemOffsetParent()[0]) {
                            // If every container has the same offset parent,
                            // use position() which is relative to this parent,
                            // otherwise use offset()
                            // compare #setDimensions
                            offsetParent = false;
                            break;
                        }
                    }
                }

                this.offsetParent = offsetParent
            }
            return this.offsetParent
        },
        setPointer: function (e) {
            var pointer = this.getPointer(e)

            if (this.$getOffsetParent()) {
                var relativePointer = getRelativePosition(pointer, this.$getOffsetParent());
                this.lastRelativePointer = this.relativePointer;
                this.relativePointer = relativePointer;
            }

            this.lastPointer = this.pointer
            this.pointer = pointer
        },
        distanceMet: function (e) {
            var currentPointer = this.getPointer(e)
            return (Math.max(
              Math.abs(this.pointer.left - currentPointer.left),
              Math.abs(this.pointer.top - currentPointer.top)
            ) >= this.options.distance)
        },
        getPointer: function (e) {
            var o = e.originalEvent || e.originalEvent.touches && e.originalEvent.touches[0]
            return {
                left: e.pageX || o.pageX,
                top: e.pageY || o.pageY
            }
        },
        setupDelayTimer: function () {
            var that = this
            this.delayMet = !this.options.delay

            // init delay timer if needed
            if (!this.delayMet) {
                clearTimeout(this._mouseDelayTimer);
                this._mouseDelayTimer = setTimeout(function () {
                    that.delayMet = true
                }, this.options.delay)
            }
        },
        scroll: function (e) {
            this.clearDimensions();
            this.clearOffsetParent(); // TODO is this needed?
        },
        toggleListeners: function (method) {
            var that = this,
                events = ['drag', 'drop', 'scroll'];

            $.each(events, function (i, event) {
                that.$document[method](eventNames[event], that[event + 'Proxy']);
            })
        },
        clearOffsetParent: function () {
            this.offsetParent = undefined
        },
        // Recursively clear container and item dimensions
        clearDimensions: function () {
            this.traverse(function (object) {
                object._clearDimensions()
            })
        },
        traverse: function (callback) {
            callback(this)
            var i = this.containers.length
            while (i--) {
                this.containers[i].traverse(callback)
            }
        },
        _clearDimensions: function () {
            this.containerDimensions = undefined
        },
        _destroy: function () {
            containerGroups[this.options.group] = undefined
        }
    }

    function Container(element, options) {
        this.el = element
        this.options = $.extend({}, containerDefaults, options)

        this.group = ContainerGroup.get(this.options)
        this.rootGroup = this.options.rootGroup || this.group
        this.handle = this.rootGroup.options.handle || this.rootGroup.options.itemSelector

        var itemPath = this.rootGroup.options.itemPath
        this.target = itemPath ? this.el.find(itemPath) : this.el

        this.target.on(eventNames.start, this.handle, $.proxy(this.dragInit, this))

        if (this.options.drop)
            this.group.containers.push(this)
    }

    Container.prototype = {
        dragInit: function (e) {
            var rootGroup = this.rootGroup

            if (!this.disabled &&
                !rootGroup.dragInitDone &&
                this.options.drag &&
                this.isValidDrag(e)) {
                rootGroup.dragInit(e, this)
            }
        },
        isValidDrag: function (e) {
            return e.which == 1 ||
                e.type == "touchstart" && e.originalEvent.touches.length == 1;
        },
        searchValidTarget: function (pointer, lastPointer) {
            var distances = sortByDistanceDesc(this.getItemDimensions(),
                    pointer,
                    lastPointer),
                i = distances.length,
                rootGroup = this.rootGroup,
                validTarget = !rootGroup.options.isValidTarget ||
                    rootGroup.options.isValidTarget(rootGroup.item, this);

            if (!i && validTarget) {
                rootGroup.movePlaceholder(this, this.target, "append");
                return true
            } else
                while (i--) {
                    var index = distances[i][0],
                    distance = distances[i][1]
                    if (!distance && this.hasChildGroup(index)) {
                        var found = this.getContainerGroup(index).searchValidTarget(pointer, lastPointer);
                        if (found)
                            return true;
                    }
                    else if (validTarget) {
                        this.movePlaceholder(index, pointer);
                        return true;
                    }
                }
        },
        movePlaceholder: function (index, pointer) {
            var item = $(this.items[index]),
            dim = this.itemDimensions[index],
            method = "after",
            width = item.outerWidth(),
            height = item.outerHeight(),
            offset = item.offset(),
            sameResultBox = {
                left: offset.left,
                right: offset.left + width,
                top: offset.top,
                bottom: offset.top + height
            }
            if (this.options.vertical) {
                var yCenter = (dim[2] + dim[3]) / 2,
                    inUpperHalf = pointer.top <= yCenter;
                if (inUpperHalf) {
                    method = "before";
                    sameResultBox.bottom -= height / 2;
                } else
                    sameResultBox.top += height / 2;
            } else {
                var xCenter = (dim[0] + dim[1]) / 2,
                    inLeftHalf = pointer.left <= xCenter;
                if (inLeftHalf) {
                    method = "before"
                    sameResultBox.right -= width / 2;
                } else
                    sameResultBox.left += width / 2;
            }
            if (this.hasChildGroup(index))
                sameResultBox = emptyBox;
            this.rootGroup.movePlaceholder(this, item, method, sameResultBox);
        },
        getItemDimensions: function () {
            if (!this.itemDimensions) {
                this.items = this.$getChildren(this.el, "item").filter(
                    ":not(." + this.group.options.placeholderClass + ", ." + this.group.options.draggedClass + ")"
                ).get();
                setDimensions(this.items, this.itemDimensions = [], this.options.tolerance);
            }
            return this.itemDimensions;
        },
        getItemOffsetParent: function () {
            var offsetParent,
                el = this.el;
            // Since el might be empty we have to check el itself and
            // can not do something like el.children().first().offsetParent()
            if (el.css("position") === "relative" || el.css("position") === "absolute" || el.css("position") === "fixed")
                offsetParent = el;
            else
                offsetParent = el.offsetParent();
            return offsetParent;
        },
        hasChildGroup: function (index) {
            return this.options.nested && this.getContainerGroup(index)
        },
        getContainerGroup: function (index) {
            var childGroup = $.data(this.items[index], subContainerKey)
            if (childGroup === undefined) {
                var childContainers = this.$getChildren(this.items[index], "container");
                childGroup = false;

                if (childContainers[0]) {
                    var options = $.extend({}, this.options, {
                        rootGroup: this.rootGroup,
                        group: groupCounter++
                    });
                    childGroup = childContainers[pluginName](options).data(pluginName).group;
                }
                $.data(this.items[index], subContainerKey, childGroup);
            }
            return childGroup;
        },
        $getChildren: function (parent, type) {
            var options = this.rootGroup.options,path = options[type + "Path"],selector = options[type + "Selector"];

            parent = $(parent);
            if (path)
                parent = parent.find(path)

            return parent.children(selector)
        },
        _serialize: function (parent, isContainer) {
            var that = this,
                childType = isContainer ? "item" : "container",

                children = this.$getChildren(parent, childType).not(this.options.exclude).map(function() {
                    return that._serialize($(this), !isContainer);
                }).get();

            return this.rootGroup.options.serialize(parent, children, isContainer);
        },
        traverse: function (callback) {
            $.each(this.items || [], function (item) {
                var group = $.data(this, subContainerKey);
                if (group)
                    group.traverse(callback);
            });

            callback(this);
        },
        _clearDimensions: function () {
            this.itemDimensions = undefined;
        },
        _destroy: function () {
            var that = this;

            this.target.off(eventNames.start, this.handle);
            this.el.removeData(pluginName);

            if (this.options.drop)
                this.group.containers = $.grep(this.group.containers, function(val) {
                    return val != that;
                });

            $.each(this.items || [], function() {
                $.removeData(this, subContainerKey);
            });
        }
    }

    var API = {
        enable: function () {
            this.traverse(function(object) {
                object.disabled = false;
            });
        },
        disable: function () {
            this.traverse(function(object) {
                object.disabled = true;
            });
        },
        serialize: function () {
            return this._serialize(this.el, true);
        },
        refresh: function () {
            this.traverse(function(object) {
                object._clearDimensions();
            });
        },
        destroy: function () {
            this.traverse(function(object) {
                object._destroy();
            });
        }
    }

    $.extend(Container.prototype, API);

    /**
     * jQuery API
     *
     * Parameters are
     *   either options on init
     *   or a method name followed by arguments to pass to the method
     */
    $.fn[pluginName] = function (methodOrOptions) {
        var args = Array.prototype.slice.call(arguments, 1);

        return this.map(function () {
            var $t = $(this),
                object = $t.data(pluginName);

            if (object && API[methodOrOptions])
                return API[methodOrOptions].apply(object, args) || this;
            else if (!object && (methodOrOptions === undefined ||
                typeof methodOrOptions === "object"))
                $t.data(pluginName, new Container($t, methodOrOptions));

            return this;
        });
    };
    
}(jQuery, window, "sortable");
